LVIS Stent Shows Strong Occlusion Rates but Real Risks in Wide-Necked Aneurysms

Wide-necked brain aneurysms are among the hardest targets in neurovascular medicine. When the neck of an aneurysm exceeds 4 millimeters or the dome-to-neck ratio falls below 2, coils placed during embolization can slip back into the parent artery, and the procedure becomes technically precarious. A new single-center retrospective study from Tangshan Workers’ Hospital, published in the Chinese Neurosurgical Journal, reports that the low-profile visualized intraluminal support (LVIS) stent, a braided self-expanding nitinol device, achieved high immediate occlusion rates when used to assist coiling in 61 consecutive patients, while also revealing a sobering complication profile that the authors themselves say underscores the need for prospective comparative research.

The study enrolled patients treated between January and December 2023, all of whom underwent LVIS stent-assisted coiling within 72 hours of symptom onset or definitive diagnosis. The cohort comprised 35 patients with acutely ruptured aneurysms and 26 with unruptured lesions. The ruptured group, 31 women and 4 men with a mean age of 60.17 years, presented with severe headache, vomiting, neurological deficits, altered consciousness, or seizures, and their pre-treatment modified Rankin Scale (mRS) scores ranged from 0 to 4. The unruptured group, 22 women and 4 men with a mean age of 57.4 years, consisted mostly of incidental findings; 23 of 26 patients, or 88.5 percent, were asymptomatic.

Anatomically, the aneurysms clustered in predictable territory. Nearly all unruptured lesions sat in the anterior circulation, with the ophthalmic artery segment (C6) the most common site at 69.2 percent of cases, followed by the posterior communicating artery segment at 26.9 percent. Among ruptured aneurysms, 94.3 percent were in the anterior circulation, and the posterior communicating artery alone accounted for 82.9 percent, frequently displaying irregular, lobulated morphology. Two neuroradiologists independently reevaluated every pre-procedural digital subtraction angiogram, with a senior physician resolving disagreements, and wide-necked anatomy was confirmed against morphometric criteria of neck width of at least 4 millimeters or a dome-to-neck ratio below 2.

The headline angiographic result was strong. Immediate complete occlusion, defined as Raymond-Roy Occlusion Classification (RROC) class I, was achieved in 80.0 percent of ruptured aneurysms (28 of 35) and 84.6 percent of unruptured aneurysms (22 of 26); the remainder reached class II, a residual neck, with no class III residual aneurysms reported. Angiographic follow-up at 6 to 12 months was available for 27 patients, an overall rate of 44.3 percent, and every aneurysm that started as complete occlusion remained stably occluded. Two of the four initial class II lesions improved to complete occlusion during follow-up, one in each group, suggesting progressive aneurysm healing after the braided stent’s flow-disruptive effect.

Functional outcomes diverged sharply by rupture status. In the ruptured cohort, the proportion of patients with favorable outcomes, mRS 0 to 1, rose from 57.1 percent at discharge to 77.1 percent at 3 to 6 months, while moderate-to-severe disability fell from 28.6 percent to 14.3 percent, with no deaths during follow-up. In the unruptured group, 96.2 percent of patients were discharged with mRS 0 to 1, and all 25 survivors maintained that level at follow-up. But the aggregate safety figures demand attention: procedure-related morbidity, defined as mRS 3 to 5 at discharge, was 16.4 percent overall (10 of 61), with every morbidity case in the ruptured group, and procedure-related mortality was 1.6 percent, a single death.

That death occurred in an unruptured aneurysm patient and traced back to incomplete stent apposition (ISA), a technical finding the authors treat as a central lesson. Incomplete apposition was identified on conventional angiography in 6 of 61 patients, 9.8 percent, and was managed with gentle microguidewire massage rather than balloon angioplasty. In the fatal case, mild-to-moderate malapposition persisted after deployment despite corrective attempts. The patient developed new neurological complaints in the early postoperative period; repeat angiography showed no major large-vessel obstruction, but over the following 3 to 5 days the neurological state declined, and in-stent thrombosis with parent artery occlusion was confirmed. Mechanical thrombectomy failed to achieve recanalization, and the patient died after a secondary cerebral hemorrhage. The authors note this case occurred despite adequate pre-procedural platelet function testing, illustrating that even favorable laboratory parameters do not eliminate thrombotic risk.

The antithrombotic protocols differed by rupture status and reflect the competing hazards of ischemia and rebleeding. Unruptured patients received at least 3 days of dual antiplatelet therapy with aspirin and clopidogrel before surgery, guided by light transmission aggregometry, with non-responders switched to higher-dose aspirin or ticagrelor. Ruptured patients received no pre-operative oral antiplatelet loading in any case, to avoid aggravating hemorrhage in the acute phase of subarachnoid hemorrhage; instead, a 0.4 mg intra-arterial tirofiban bolus was given after stent deployment, followed by a 24-to-48-hour intravenous infusion bridging to oral dual therapy. Two ruptured patients, 5.7 percent, developed intraprocedural thrombosis that was managed successfully with a stepwise rescue protocol using the same bolus dose, local microcatheter delivery, and infusion escalation, without permanent deficits. Symptomatic thromboembolic events across the whole cohort totaled 4.9 percent, a figure the authors compare with the 4.6 percent rate reported in the prospective multicenter LEPI study of LVIS devices.

Beyond the clinical results, the study’s most distinctive contribution is a computational fluid dynamics (CFD) analysis performed on a subset of 14 patients, 4 ruptured and 10 unruptured, who had both baseline and follow-up angiographic data. After LVIS implantation, relative inflow within the aneurysm fell from 0.17 to 0.07, the proportion of aneurysm volume exposed to high relative flow dropped from 65.8 percent to 9.2 percent, and mean wall shear stress declined from 4.28 Pa to 1.31 Pa, all statistically significant. Critically, these hemodynamic changes persisted at 6-month follow-up, remaining significantly different from pre-operative values, supporting the idea that the stent creates an intra-aneurysmal environment unfavorable to sustained flow activity and thereby favorable to thrombosis and durable healing.

The authors place these findings in context carefully. The LVIS stent’s metal coverage of roughly 23 percent exceeds that of laser-cut stents such as the Enterprise, and prior comparative CFD work found a single LVIS stent reduced intra-aneurysmal flow more than two Enterprise stents, though less than a dedicated Pipeline flow diverter. That intermediate flow-diversion profile, combined with the antiplatelet burden that strong flow diverters demand, may make the LVIS stent attractive in ruptured cases where intensive antiplatelet regimens are hazardous. The authors also highlight emerging high-resolution three-dimensional fusion imaging, citing a 2024 study that detected edge malapposition in 47.5 percent and trunk malapposition in 27.5 percent of LVIS deployments, rates far higher than conventional angiography reveals, suggesting mild malapposition is routinely missed in standard practice.

The limitations are stated plainly and should temper any enthusiastic reading. The retrospective, single-center design precludes causal inference, the mixed cohort of ruptured and unruptured aneurysms introduces clinical heterogeneity, and the 44.3 percent angiographic follow-up rate may have selected patients with better outcomes, potentially inflating the durability estimates. The CFD subset was exploratory and could not link specific flow characteristics to clinical endpoints such as recurrence, and stent apposition was judged by conventional angiography alone. Within those constraints, the study offers preliminary observational evidence that LVIS stent-assisted coiling delivers high initial occlusion rates, meaningful functional recovery in ruptured cases, and durable hemodynamic modification, while its complication record, one fatal stent thrombosis and a morbidity burden concentrated in ruptured patients, makes clear that technical success, particularly optimal stent apposition, remains the decisive variable. The authors call for prospective, controlled studies to establish the technique’s true safety and efficacy profile.

Subject of Research: Retrospective evaluation of LVIS stent-assisted coiling for intracranial wide-necked aneurysms

Article Title: Safety and hemodynamic efficacy of the LVIS stent in the endovascular treatment of intracranial wide-necked aneurysms: a single-center retrospective study

Article References: Dong, B., Xu, X., Wang, D., Pei, J., Zheng, Y., Gao, Y. H., & Gao, Z. (2026). Safety and hemodynamic efficacy of the LVIS stent in the endovascular treatment of intracranial wide-necked aneurysms: a single-center retrospective study. Chinese Neurosurgical Journal, 12(1), Article 19. https://doi.org/10.1186/s41016-026-00435-9

Image Credits: AI Generated

DOI: 10.1186/s41016-026-00435-9

Keywords: LVIS stent, intracranial aneurysm, wide-necked aneurysm, stent-assisted coiling, computational fluid dynamics, wall shear stress, subarachnoid hemorrhage, incomplete stent apposition, Raymond-Roy occlusion, dual antiplatelet therapy, tirofiban, endovascular treatment